Geologic time scale

Front

Absolute dating

Back

Finding out how old a rock is in actual years

Front

Relative dating

Back

Finding out how old one rock is compared to another rock

Front

Mass extinction

Back

The end of a group of organisms

Front

Fossils

Back

Remains of an organism that lived in the past

Front

Geologist

Back

A scientist who studies Earth’s crust as well as the processes and history that shaped it.

Front

Index fossils

Back

Special fossils that indicate to geologists the boundaries of geological time.

Front

Law of Superposition

Back

The law that says the newest rock layers are on top of the older ones in the arrangement of sedimentary rock.